Plant Biotechnology 8

Question 1

What do agronomic traits include?

Answer 1

Yield
Herbicide tolerance
Disease and pest resistance

Question 2

What do quality traits include?

Answer 2

Processing
Shelf life
Nutritional quality

Question 3

Name 3 novel products that can be grown in plants

Answer 3

Oils
Proteins
Polymers ie. plastics

Question 4

Describe roundup ready

Answer 4

Broad spectrum herbicide made by Monsanto
Glyphosate
Acts by inhibiting a chromoplast enzyme

Question 5

What are advantages of HT (herbicide tolerant) crops?

Answer 5

Enhanced crop productivity

Encourages ’no-till’ agriculture – reducing soil erosion and lowering fuel costs and greenhouse gas emissions

Question 6

What are disadvantages of HT (herbicide tolerant) crops?

Answer 6

Increased use of Roundup

Possible reduction in biodiversity

Question 7

What bacteria is most commonly used for insect resistance?

Answer 7

Bacillus thuringiensis (Bt)

Question 8

How does Bacillus thuringiensis (Bt) work?

Answer 8

Its spores contain a crystalline protein that kills insects

1. Larva consumes toxin
2. Crystals solubilized and toxin activated by proteolytic cleavage in mid-gut
3. Toxin binds to specific receptors
4. Binding triggers cell death in mid-gut lining
5. Septicaemia follows and larva dies

Question 9

Which gene encode the Bt toxins?

Answer 9

Cry genes

Question 10

What are the advantages of using Bt crops?

Answer 10

reduced financial cost due to less pesticide use
Reduced environmental impact
Improved health of farmers
Improved food quality

Question 11

What are the disadvantages of using Bt crops?

Answer 11

Selection pressure for resistant pests

Possible effect on non target insects

Question 12

What is golden rice?

Answer 12

Provitamin A-enriched rice variety

Question 13

Where do humans normal get vitamin A from?

Answer 13

Provitamin A from plants

From animal products containing vitamin A

Question 14

Describe what happens when someone has a vitamin A deficiency

Answer 14

Night-blindness
Dry eyes (xerophthalmia)
Increased susceptibility
Developing countries

Question 15

What is a main cause of VAD?

Answer 15

Low vitamin A content of the rice grain as it is staple diet all over the world

Question 16

Why does rice have little vitamin A?

Answer 16

Due to little of β-carotene

There are 4 missing enzyme catalysed steps

Question 17

How was rice made that is rich in β-carotene (golden rice)?

Answer 17

Introduced two daffodil genes and an Erwinia gene under the control of endosperm-specific promoters into rice

Question 18

Golden rice 2 can provide how much of a childs RDA of Vitamin A?

Answer 18

50%

Question 19

What is an advantage of golden rice?

Answer 19

saves people from going blind

Question 20

What is a disadvantage of golden rice?

Answer 20

Reinforces dependancy on rice diet

Question 21

What are aphids?

Answer 21

Major agricultural pests, damaging crops and carrying important plant viruses

Question 22

What is the aphid alarm pheromone?

Answer 22

A volatile, non-toxic chemical produced by aphids in response to attack.

Question 23

What is an edible vaccine?

Answer 23

Vaccines where the antigen is produced in a transgenic plant and can be administered orally.

Question 24

What is an advent of edible vaccine?

Answer 24

Production is efficient and easily scaled up

Don’t require refrigeration

Question 25

How are edible vaccines developed for the measles virus?

Answer 25

Select an antigen surface exposed protein targeted during the immune response
Isolate the MV-H gene
Express the gene in an edible transgenic plant
Test effectiveness by feeding the lettuce to mice
Assay for the presence of anti-MV-H antibodies in mice